{"id":"CVE-2026-107843","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-107843","generatedAt":"2026-10-27T23:50:46.417Z","title":"From version 4.1.0 until 5.3.50 and 5.7.12, ModuleRegistration::compile() enters its follow-up registration branch on any POST to a page containing the registration module without verifying FORM_SUBMIT or the preceding captcha result.…","description":"Contao is an Open Source CMS. From version 4.1.0 until 5.3.50 and 5.7.12, ModuleRegistration::compile() enters its follow-up registration branch on any POST to a page containing the registration module without verifying FORM_SUBMIT or the preceding captcha result. resendActivationMail() can then invoke OptInToken::send() without rate limiting, allowing an unauthenticated attacker to cause repeated activation emails to be sent to an address with a pending registration and to determine whether that pending registration exists. The branch is reachable only when reg_activate is enabled and the target has an unconfirmed registration and opt-in token. This issue is fixed in versions 5.3.50 and 5.7.12.","published":"2026-10-09T20:17:10.000Z","lastModified":"2026-10-16T17:17:04.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N"},"cwe":["CWE-204","CWE-770"],"affected":[],"epss":{"score":0.0027,"percentile":0.19033,"date":"2026-10-26","history":[{"date":"2026-10-10","score":0.00255,"percentile":0.15787}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.27%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-09T20:17:10.000Z","detail":{"score":"5.3","severity":"MEDIUM","publishedAt":"2026-10-09T20:17:10.167Z"},"summary":"New CVE, medium severity (CVSS 5.3)."}],"references":[{"url":"https://github.com/contao/contao/commit/2ea6117f9049db7221679251cfc41e67d941a74b","source":"security-advisories@github.com"},{"url":"https://github.com/contao/contao/releases/tag/5.3.50","source":"security-advisories@github.com"},{"url":"https://github.com/contao/contao/releases/tag/5.7.12","source":"security-advisories@github.com"},{"url":"https://github.com/contao/contao/security/advisories/GHSA-mfxh-vp55-7gc6","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-107843","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}